Abstract [en]

The Rashba effect leading to subband splitting in quantum wells is frequently taken to be proportional to some average electric field. We here show that taking the spatial variation of the electric field into account gives important effects. In particular we demonstrate that one can apply a moderate electric field to a wide modulation-doped quantum well and get an order-of-magnitude enhancement of the Rashba splitting characteristic of the built-in interface field. For small asymmetry the wave function localization and spin projection of a subband can be rapid functions of the in-plane wave vector.